Vacuum cleaner dust bag



July 13, 1943.

R. K. OSTERDAHL VACUUM CLEANER DUST BAG Filed O61.- 25. 1941 lNvENjrORWWfiM BY f 4,; AORNEY Patented July 13, 1943 UNITED VACUUM CLEANER DUSTBAG Ragnar Konstantin osteraam, Store Essingen. Sweden ApplicationOctober 25, 1941, Serial No. 416,473 In Sweden March 1, 1939' 2 Claims.

The present invention relates to dust-collecting vacuum cleaner bags,more particularly of the type comprising a dust-separating filter and aperforated supporting jacket arranged on the outside of said filter. Itis essential that these bags should be very cheap, especially if theyare of the kind which is to be thrown away after use. Both filter andsupporting jacket should therefore be made of as cheap material aspossible. A cheap bag material of this kind is paper. However, theperforations of the paper should not lie too close together, as this maycause the jacket of the bag to burst, when it is exposed to suctionaction. With the perforations properly spaced for strength, however, thefilter is not always utilized to the fullest, because the air is likelyto pass through the comparatively small portions of the filter locateddirectly opposite the orifices of the jacket, whereas those portions ofthe filter which are covered by the remaining parts of the jacket letthrough a less quantity of air, thus separating comparatively smallquantities of dust.

The present invention relates to an efficient device for eliminatingthis drawback, that is for effecting a uniform distribution of thepassage of air and, consequently, an increased filtering capacity.

In conformity therewith the device according to the invention ischaracterized substantially in that the jacket of the bag is formed inits interior with supports adapted to bear against the filter and keepit at a distance from the perforations of the jacket. The supports mayconsist of inwardly bent tongues partially cut from the jacket of thebag and formed during the formation of the perforations. To bring aboutan efficient supporting action these tongues should preferably be foldedbackwardly towards the jacket of the bag. The supporting effect of thetongues may be increased, if they are arched, folded or corrugated. Thefilter lining of the bag may consist of one or more superposed sheets orlayers. v

According to the invention the dust-collecting bag may be made in suchmanner that tongues are punched out and folded inwardly and backwards ina sheet or band of paper or similar thin material, a filter sheet orfilter band being made of one or more superposed layers of wadding ofwood cellulose, of which layers one or more or all are perforated andthus loosened, whereupon the filter is applied to the sheet or the bandof paper or the like, and the sheet formed in this manner, or cut-offportions of the band thus formed, are

shaped into vacuum cleaner dust bags with inside filters.

The accompanying drawing shows some embodiments of the invention.

Fig. 1 is a side view, partly in section, of a dust-collecting bagconstructed according to the invention.

Fig. 2 is a sectional view on a larger scale of a lower part of the bag.

Figs. 3 and 4 show on a very enlarged scale a front view and a sectionalview of a part of the wall of the bag.

Figs. 5-7 are views corresponding to Fig. 3 and.

showing other embodiments.

Figs. 8 and 9 are views corresponding to Figs. 3 and 4 but relating toanother embodiment.

The jacket I of the dust-collecting bag shown in Fig. 1 is assumed to bemade of thin paper or similar material. The bottom 3 of the has consistsof portions of the bag jacket turned-in crosswise and in pairsrelatively to each other. The inner side of the jacket of the bag iscovered by a filter 2 comprising a plurality of superposed thin sheetsor layers. As a filter material use may be made of wadding of cotton orpreferably wood cellulose. The fibres of the wadding of wood cellulose,are, if desired, loosened, for example, by perforation with needles orsome similar treatment.

At the lower end of the bag the filter sheets, except the innermostsheet 4, are pasted to each other. The edge of the outermost sheetbearing against the jacket I is pasted to this jacket. The edge of theinnermost filter sheet not being pasted facilitates the manufacture ofthe bag and at the same time prevents the bag in its folded state(according to Fig. 1) from being pasted together owing to the transferof paste at the lower edges of the sheets. At the upper edge of thefilter all layers may be pasted to each other and to the jacket of thebag. A band 5 folded in its transverse direction is pasted to the upperedges of the filter 2 and the jacket I of the bag, and may be folded outso as to form a plane, annular flange for fixing the bag to the vacuumcleaner.

The jacket I of the bag is perforated by punching out flaps Gwhich arefolded inwards (Figs. 3 and 4) and backwards towards the jacket of thebag so as to form resilient supports for the filter 2. The tongues maybe given an arched shape which enhances their supporting effect. Toincrease the height of the filter supports formed by the tongues thelatter may be bent down to contact the inner surface of the jacket (Fig.5). rolled up on themselves (Fig. 6) or folded back on themselves (Fig.7).. I! desired, the tongues may be corrugated in their longitudinaldirection. The supporting action of the tongues keeps the filter 2 atsome distance from the jacket of the bag so that its capacity ispractically wholly utilized. In fact. the air can flow transverselythrough all parts of the filter, and then through the intermediatespaces 1 to those orifices I in the jacket of the bag which are formedby the folding-in of the tongues. When the bag is exposed to outersuction action, the filter is pressed against the tongues which pressresiliently against the jacket of the bag, without, however, the filterbeing forced closely/against said jacket. Each time the suction actionceases, the tongues rebound resiliently. The movements or the tonguesand the inherent resiliency of the filter (especially if it is made ofwood cellulose) produce in the filter movements by means of which dustis loosened from the filter. The arrangement of the supports thus makesthe filter to some extent self-cleaning.

This dust-collecting bag may be made on a somewhat modified machineintended for the manufacture of ordinary paper bags. In this case thetongues 3 are punched out and folded inwards and backwards in the sheetor band of paper or the like which is to make up the jacket of the bag.On the machine there is simultaneously made a filter sheet or filterband of one or more superposed layers of wedding of wood cellulose, ofwhich layers one or more are perforated so as to loosen the filter andgive it the desired resilient properties. The sheet or band 01' filtermaterial thus produced and treated is joined to the perforated sheet orband in such a manner that the filter is placed on the backwardly foldedtongues and is fastened to the perforated band or sheet in the mannerdescribed above. The folded collar (if desired in the shape of a band)is also pasted to the sheet or band thus formed. 01 the sheet thusshaped or the sheets cut out 01' the band the bag is then formed. itsbottom being turned in crosswise and tolded up so that the bag shown inFig. 1 is obtained.

According to Figs. 8 and 9 the above-mentioned increase in the capacityof the filter is obtained by providing the jacket or the bag withinwardly directed elevations in the shape of impressed corrugations 9extending between the orifices i of the jacket of the bag.

What I claim is:

1. In a vacuum cleaner dust bag, an outer jacket member, a lining offiltering material supported within said jacket, said Jacket beingformed with a plurality of apertures, and tongues integral at one endwith said Jacket at the edges of said apertures, said tongues beingturned away from said apertures at angles eater than to thereby spacesaid filtering material from the inner side of said jacket.

2. In a vacuum cleaner dust has, an outer jacket member, a lining offiltering material supported within said Jacket. said jacket beingformed with a plurality of apertures, and tongues integral at one endwith said jacket at the edges of said apertures, said tongues beingturned backwardly from said apertures and curved with the free ends ofthe tongues in contact with the inner side of said jacket and with theintermediate portions of the tongues spaced therefrom, whereby to spacesaid filtering material from the jacket.

RAGNAR KONSTANT'IN bsTERDAI-IL.

